Struct datafusion::physical_plan::expressions::MinAccumulator

pub struct MinAccumulator { /* private fields */ }

An accumulator to compute the minimum value

Implementations

impl MinAccumulator

pub fn try_new(datatype: &DataType) -> Result<MinAccumulator, DataFusionError>

new min accumulator

Trait Implementations

impl Accumulator for MinAccumulator

fn state(&self) -> Result<Vec<AggregateState, Global>, DataFusionError>

Returns the state of the accumulator at the end of the accumulation. in the case of an average on which we track sum and n, this function should return a vector of two values, sum and n.

fn update_batch(
    &mut self,
    values: &[Arc<dyn Array + 'static>]
) -> Result<(), DataFusionError>

Updates the accumulator’s state from a vector of arrays.

fn merge_batch(
    &mut self,
    states: &[Arc<dyn Array + 'static>]
) -> Result<(), DataFusionError>

updates the accumulator’s state from a vector of states.

fn evaluate(&self) -> Result<ScalarValue, DataFusionError>

returns its value based on its current state.

fn size(&self) -> usize

Allocated size required for this accumulator, in bytes, including Self. Allocated means that for internal containers such as Vec, the capacity should be used not the len

fn retract_batch(
    &mut self,
    _values: &[Arc<dyn Array + 'static>]
) -> Result<(), DataFusionError>

Retracts an update (caused by the given inputs) to accumulator’s state. Inverse operation of the update_batch operation. This method must be for accumulators that should support bounded OVER aggregates.

impl Debug for MinAccumulator

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.